If it's possible to save and access files from any browser, from any location, set up an automatically syncing folder, and selectively share access with others, then you have an alternative to dropbox, and all the other cloud personal storage services. All of which nextcloud can do.
The differences just mean you don't prefer that particular alternative the same way as if you didn't like the color scheme, or more realistically say the need to make a microsoft account for onedrive, or the way google probably scans the contents of google drive etc.
They are all still alternatives with various pros & cons.
Setting up your own nextcloud on a publicly accessible service is no different.
The cons like effort and cost are noted.
The pro is there is no one else in control of your stuff and it's impossible to lose your account due to some age verification, or any other reason like "communiy standards" or billing dispute. The worst that can happen is your hosting provider can drop you, but that is a commodity and there are infinite other hosting providers and methods. Keep your own mirror so you don't care even if the hosting provider deletes everything.
If any alternative to dropbox has to be identical in every detail to qualify, then it has exactly the same problems as well. An alternative actually has to be different in some way or else it's not an alternative but just more of the same, and there is no point in that.